1. Field of the Invention
The present invention relates to a wind turbine system and method of operating a wind turbine system. More particularly, the present invention relates to a method and system for operating a vertical-axis wind turbine.
2. Description of the Related Art
A wind turbine or windmill converts the kinetic energy in wind into electric energy. There are two general types or categories of wind turbines: horizontal-axis wind turbines and vertical-axis wind turbines. As the terms imply, a horizontal-axis wind turbine includes a sail or one or more blades that rotates about a horizontal axis, while a vertical-axis wind turbine includes a sail or one or more blades that rotates about a vertical axis.
Since horizontal-axis wind turbines must be pointed into the wind, they are ineffective in locations where wind directions are highly variable. Because vertical-axis wind turbines do not suffer from this same deficiency, they are appropriate for installation on top of buildings and similar locations where the wind directions are variable.